Few athletic feats are as pretty, graceful, and as impressive as a great unilateral (1-leg) jump. The smooth effortless liftoff and seeming ease of the maneuver comes as close to mimicking true flying as anything else.
Unfortunately, for the most part, as much as any other demonstration of athleticism, the 1 leg jump also has over time been something you either have or you don't. People are either naturally good at it or they're not - usually from an early age. Take a group of 15 yr. olds out to a basketball court and ask them to jump as high as possible at the rim with no limits on how many steps they take or what style of jump they use. What you’ll find is some people do better going off both feet, some do better going off 1, and a handful (like Michael Jordan), excel either way. Those that inherently excel in the 1 foot jump will tend to have a greater gap between the 2 styles. In my experience, it’s relatively uncommon that the people that jump significantly higher off both feet ever "convert" to being excellent unilateral jumpers, although the reverse is not terribly uncommon. It is certainly possible to improve the bilateral (2-leg) vertical jump substantially. These days gains of 15 inches or more over a period of time are relatively common. Physical growth and physical maturity in conjunction with consistent training will improve either style. However, most of the training that improves jumping ability tends to improve bilateral jumping to a greater extent than unilateral jumping.
Fortunately, I do think there is hope. Although not everyone can be an elite high jumper, I do believe most people can significantly improve their unilateral jump, and understanding and improving it is what this article is all about.
==================================================== Defining The Problem
First, let's define the problem: There are an assortment of muscular and structural factors which contribute positively or negatively to unilateral jumping. Let's start off by taking a look at what happens in the unilateral jump and the differences between it and the bilateral jump:
You run up to a predetermined take off point, plant your foot, and basically take off one leg like you're doing a lay up. If you think of the action of a pole vaulter and imagine the pole vault is the leg of an athlete you have a somewhat accurate picture of what takes place in a unilateral jump. The foot plants and the body levers over the plant leg and rebounds off the plant foot up into the air. After the plant, and as you begin to leave the ground, the action of the plant leg is fairly similar to a bull pawing the ground, pushing down and back, which involves a good degree of hip extension, much like a cross between a single leg squat and single leg reverse hyper. Thus, it should be no surprise that science has found that in comparison to the bilateral jump the unilateral jump favors increased activation of the hip extensor musculature, or the glutes. (1)
What other differences exist? Well, based on my research and observations, the main difference is the muscles acting on the knee and ankles (quads and calves) are unable to contribute as much positive energy to the actual jump. They do act eccentrically during your plant phase to help you absorb the force and avoid collapsing when you plant, yet when you perform a bilateral jump you’re able to get more wind-up and generate significantly more “oomph” from your quads and calves. You’re able to explode thru the positive motion like you’re doing a ¼ squat and pop off the balls of your feet – and you’re able to do it with both legs instead of just 1. In the unilateral jump all you can really do is plant 1 foot and generate a quick push.
In my experience it is possible (although relatively uncommon), for a glute deficient, hamstring deficient athlete to jump well off both feet. Having good power in the quads and/or calves can make up for their deficiencies. The same is less true for the unilateral jump, - guys who are extremely quad dominant and glute/hamstring deficient don’t tend to excel at it - although these deficiencies can sometimes be masked by having superior structural qualities, as you’ll find out in the next section. But in a nutshell the glutes and hip extensors in general are more important than the quads for the unilateral jump then they are for the bilateral variations, and leverage is more important. You have to be able to generate enough additional leverage to make up for the fact that you’re only using one leg to generate power.
Now let’s discuss the structural factors responsible for that leverage: By structural I’m referring to the length of your bones, muscle attachment points, length and makeup of your tendons, and your posture. Some of these you can do nothing about while some you can influence to a decent degree.
Go out and do a few unilateral jumps and you’ll probably find if you go fast enough and hard enough in your approach you can induce a good degree of pain in your ankles or knees. This is due to the impact forces involved, which throw a lot of force onto the knees, ankles, and hips. In fact, these forces can be up to 10 x bodyweight! One of the keys to a good unilateral jump is being able to keep a somewhat stiff leg at impact and not allow the knee to buckle too much. This requires the ability to absorb forces in the ankles and knees, of which strength in the quadriceps is a primary variable and a consistent focus amongst high jumpers.
However, this is also influenced by your body structure, since the structure in large part determines how efficiently your body deals with force. The structure of your hips, limbs, and feet determine how your feet impact the ground, how the joints are aligned at impact, how much stress is absorbed into the joints, and in large part how much leverage you’re able to generate from a given amount of muscular force. People that unilaterally jump well tend to inherently have a structure and posture that lessens impact stress in the ankle, knee, and hip when they plant and optimizes their leverage when they jump. In other words, if you've ever skipped rocks on a pond of water good uni-lateral jumpers function like a longer ultra thin rock. They inherently deflect and leverage force well. Let’s take a look at some of these structural factors:
Leg length: It would obviously be fairly difficult to effectively pole vault with a pole that is only 2-feet long. You simple don’t have a long enough lever to swing up and over the bar. By the same token, individuals with longer legs have better leverage in the unilateral jump. The best high jumpers typically have disproportionately long thigh bones. The shorter your legs are the less likely you are to be a good unilateral jumper, although there are exceptions.
Hip width: The wider the hips are the greater the natural deviation the center of gravity is at the plant. When a person with thin hips plants their foot their center of gravity is more easily directed over their plant foot. Ideally you want thin hips, but again, there are exceptions. This does help explain why you don’t see many women who jump off 1 foot as well as they do 2, as they inherently have a wider relative hip structure.
Tendon length and stiffness: Although in my opinion not a make or break factor, the length of the Achilles tendon does have some relevance, as it explains the ability of kangaroos to hop around with little effort. The tendon acts like a rubber band. However, plenty of excellent high jumpers don’t appear to have relatively lengthy Achilles tendons compared to the rest of their body. A more important factor is tendon stiffness. In this sense the word stiffness does not mean lack of flexibility. To grasp the concept of tendon stiffness think of the difference between an ultra thin rubber band and a thick rubber band. The thick rubber band generates more force when pulled back, and is more difficult to deform. Top high jumpers have been found to have Achilles and patellar tendons up to 4 x stiffer than normal. This allows them to jump using faster approach speeds and more forceful take offs, as they deal with and generate force better. Tendon stiffness improves with regular training but the extreme deviation from the norm seen in elite high jumpers in this area is largely genetic.
Those factors are fairly difficult for you to influence to a great degree, short of choosing the right parents. Now let’s touch on some factors you can control:
Bodyweight: With the exception of rare specimens like a young Charles Barkley, most unilateral jumpers are relatively thin and lean. Bilateral jumpers can benefit from increased muscle mass to a greater extent because increased thigh and hip size allows them to generate more power during the positive phase of the jump, and they’re able to use 2 legs to generate power instead of just 1. Increased upper body size and strength throughout the spinal erectors, shoulders, and traps also can help them (or at least doesn't hurt them), drive off the ground. The increased whole body power that comes with increased muscle mass makes up for any increased weight they gain which explains why many of the best bilateral jumpers often push 200 lbs bodyweight or better. Unfortunately, since it's more about leverage and less about strength, the unilateral jump doesn’t tend to respond well to weight gain. That doesn’t mean you need to starve yourself like an anorexic or be overtly paranoid of any muscle gain. Keep your body-fat down and restrict your muscle mass increases primarily to your glutes, hams, and quads in that order and you’ll be good to go.
Posture and muscle balance: By controlling your posture you can optimize impact stress in the ankles and knees when you plant and optimize muscular contributions to get as much leverage as possible when you jump. Unilateral jumping favors a forefoot dominant posture, which is primarily controlled by the muscles acting on the pelvis, the glutes and hip flexors. A sure sign that your posture and muscle balance are off is if you feel pain or lack of coordination when you jump. Unilateral jumping is a lot like skipping walks across the water. It's not a feat that should feel like you’re exerting a ton of effort. It should feel relatively smooth and effortless, even if your jumps aren’t extremely high.
Now let’s go over the 5 keys for increasing the unilateral jump:
A: Keep your body-fat in check
This should be self-explanatory. Anything more than 10-12% body-fat and I'd start to worry.
B: Establish glute/hip extension dominance and strength
Here you need to get your posture and muscle balance correct so you execute the movement with optimal recruitment patterns. As mentioned above, see Creating the forefoot dominant athlete for more on this topic.
C: Strengthen the quadriceps and ankles
Remember what I said about the quads helping you absorb force in the plant? You need enough strength in the relevant muscles to dampen that impact stress. The knee and ankle extensors (quads and calves) are most important, so squats, lunges, calf raises, various plyometrics and other loaded quadriceps strengthening movements are your friend here. To give you an idea, 150 lb champion high jumper Steffan Holm routinely does barbell step-ups with 400 + lbs!
One of the questions I get asked a lot is if a person wants to jump off 1-leg should they exclusively favor unilateral exercises like lunges, stepups, and bulgarian split squats in their training? Unilateral exercises are good for a lot of things and can certainly be incorporated, yet given the fact that weight training has very general affects I personally don't think there's any need to overly emphasize these lifts much more than you usually would. I'd still consider squats the foundational strength lift, as do most high jumpers. In other words, if you took 2 twin brothers competing in the high jump and one of them could only train with 1-leg lifts and the other with only 2 leg lifts I wouldn't expect to see much of any difference in their performance.
One thing that is true of the unilateral jump with regard to strength training is it does seem to respond exceptionally well to partial range movements. Exercises like half squats, lunges, and low box step-ups carry over particularly well, likely because they duplicate the knee angle that occurs in the plant, which is often a limiting factor.
D: Optimize Hip Power
What is hip power? Well, after the plant phase as you leave the ground the hip extensors kick in to give the final push. Hip power is a function of strength, speed, and movement efficiency of the hip extensors. You get the strength from exercises like the reverse hyperextension and squat, and the speed from being proficient at your movements and having a posture that allows your hip extensors to function optimally.
A good assessment into hip power are single leg horizontal bounding drills. One I really like is a single leg triple jump for distance. Stand with one foot in front of the other and push off 1 leg bounding out as far as possible. As soon as you hit the ground hop again, but this time don’t let your off leg hit the ground. Then as soon as you hit the ground jump once more. Focus more on absorbing smoothly and relaxing, like a rock skipping across water, rather than muscling the movement.
Ideally you want your standing triple jump to come close to 3 x the distance of your standing bilateral broad jump.
Note: One word of caution - I don't recommend this exercise unless you have a good strength base and a history of jump training. The impact forces on the plant foot are substantial. Less experienced athletes should stick with regular skipping variations.
The Next Step
Now, while doing all of that you also need to:
E: Hone/practice jumping technique to optimize specific leaping patterns, recruitment patterns, muscular, and tendon strength
This you accomplish by actually practicing your jumps. This does 2 things: First, it obviously enables you to practice and optimize your technique. Secondly, moreso than most athletic events, unilateral jumping is intense plyometric activity. Jumpers in the field events tend to take several days of rest between sessions of jumping, because the speed of the approach and unilateral plant sends a lot of force into the muscle tendon complex. Thus, the best plyometric exercise for a good unilateral jump, IS a unilateral jump. That doesn't mean there aren't some effective auxiliary plyometric exercises - The standing triple jump drill I described above is one of them. Others include skips, bounds, box jumps, and depth jumps. However, keep in mind these are secondary to the actual event of jumping.
===================================================== A Sample Routine
Sound complicated? Well to make it a bit easier here is a sample routine designed to increase unilateral jumping. It’s designed for an intermediate level athlete with at least 6 months strength training background. Before I get into it one caveat: Even at the more advanced levels the differences in training for the unilateral and bilateral jump are relatively miniscule. At the beginning levels the training is EXACTLY the same. So make sure you've established a strength base and have 6 months to a year of solid training under your belt before worrying about any of the stuff in this article. Having said that, here is a sample 3 week routine:
Although that routine is fairly generic and won't serve everyone well it should serve the average intermediate trainee quite effectively. If you feel you need a more comprehensive evaluation and individualized program feel free to contact me for an individualized program design
1. Contribution of the lower extremity joints to mechanical energy in running vertical jumps and running long jumps.Stefanyshyn, Nigg. Human Performance Laboratory, The University of Calgary, Alberta, Canada.
2. Scand J Med Sci Sports. 2008 Feb;18(1):23-30. Epub 2007 May 9.
Effect of habitual exercise on the structural and mechanical properties of human tendon, in vivo, in men and women.